Energy Of A Polaron In A Wurtzite Nitride Quantum Well

Recently, wurtzite nitride semiconductors are taking more attentions of many researchers because of their characters such as wider energy gap, higher break-through electric field, quicker electron saturation velocity, larger heat conductance and more steady capabilities of physics and chemistry. Furthermore, the electron-phonon interaction is found strongly influence on the character of semiconductors and their low-dimensional structures. Therefore, the researches of polaron in wurtzite nitride quantum well structure are more meaningful.In this paper, the energy levels of free polarons in the wurtzite nitride (GaN/AlxGa1-xN)quantum well structure are studied by using Lee-Low-Pines (LLP) transition. The ground state, first excited state and transition energies from first excited state to ground state are calculated as a function of well width (L) and depth (V0). The results indicate that the ground state, first excited state and transition energies rapidly decrease with increasing the well width at smaller L, but slowly at larger L, and finally approach to the bulk value of GaN. The ground state, first excited state and transition energies all slowly increase with increasing V0, and it is more visible in narrow well. It is also found that the contribution of electron-phonon interaction in wurtzite nitride quantum well structure is very large, the value (about 40meV) is much larger then that (about 3 meV) in zinc-blende (GaAs/Al_xGa_1-xAs) quantum well structure. Therefore, the contribution of electron-phonon interaction in wurtzite nitride quantum well structure should be considered when the election state in nitride GaN/Al_xGa_1-xN quantum well is discussed.